定向水平钻孔水力压裂卸压护巷技术研究及应用

Research and application of directional horizontal drilling hydraulic fracturing relief and roadway protection technology

针对工作面回采过程中及收尾后大巷难以保持稳定的问题,为了改变传统卸压方式在卸压范围、卸压时间、卸压效果等方面存在的不足,提出利用定向水平钻孔水力压裂技术进行卸压,采用理论分析和数值计算相结合的方式分析了大巷高应力产生原因,揭示了定向水平钻孔水力压裂对于工作面高支承压力转移作用机理,结果表明:工作面末采期顶板的断裂、旋转、运移、垮落等剧烈活动是造成采区大巷围岩应力集聚的主要原因;在工作面终采线实施定向水平钻孔水力压裂能够消除工作面停采后顶板破断而产生的动压能量,同时能够使得垮落带岩层及时破断冒落充填采空区,改变悬臂结构,进而降低护巷煤柱应力,现场应用取得了良好的效果。

Aiming at the problem that it is difficult to maintain the stability of the main roadway during the mining process of the working face,in order to change the shortcomings of traditional pressure relief methods in terms of pressure relief range,time and effect,it is proposed to use directional horizontal drilling hydraulic fracturing technology for pressure relief.The reasons for the high stress in the road are analyzed using theoretical analysis and numerical calculation,and the mechanism of the directional horizontal drilling hydraulic fracturing for the transfer of high abutment pressure in the working face is revealed.It is concluded that the main reason for the stress concentration in the surrounding rock of the main roadway in the working area is the violent activities such as the fracture,rotation,migration and collapse;The implementation of directional horizontal drilling hydraulic fracturing in the mining stop line of the working face can eliminate the release of dynamic pressure energy caused by the breaking of the roof after the mining stop of the working face.The rock layers in the caving zone can be broken in time to fill the goaf and reduce the risk of the stress of coal pillar,which has achieved favorable results in field application.